Embedding laser generated GaAs nanocrystals in perovskite wires for enhanced charge transport and photodetection

Solution-processed perovskite wires are attractive candidates for photodetectors (PDs) due to their simple processibility as well as one-dimensional (1D) geometry with desirable charge carrier transport. However, the performance of the perovskite PDs is generally restricted by the charge carrier transport and extraction efficiency. Herein, we demonstrate that the charge transport and the consequent photodetection performance of MAPbI₃ perovskite wires can be effectively enhanced by incorporating nanocrystals (NCs) of GaAs—a semiconductor with high charge carrier mobility. Taking advantage of the pulsed laser irradiation technique, we successfully fabricate ligand-free GaAs NCs with a size of ∽7 nm and homogeneously embed them in MAPbI₃ perovskite wires through a simple solution-processed synthesis route. Compared with the pristine perovskite wires, the GaAs NCs modulated perovskite wires show improved charge carrier transport with the mobility rising from 1.13 to 3.67 cm² V⁻¹ s⁻¹, and the resultant PD shows significant improvement in responsivity and detectivity. This study provides a new strategy for improving optoelectronic properties of halide perovskite materials and optimizing the device performance.